How To Find Prime Numbers In Python
This article will learn how to check if a number is prime or not in Python. Usually, we all know some common methods using library functions or without using library functions. But how many of us know that there are 6 means to check a prime number. Possibly some of us will be familiar with some methods. Simply this article will teach you all the possible ways. Let united states of america move on to bank check if a number is prime or not.
In the number organization, we have ii types of numbers. They are Prime and composite. Prime numbers are the numbers that are not the product of any other numbers. These numbers are e'er natural numbers. For example, 13 is a prime number. Because we cannot get this number as a production of any other two numbers except to the product of one, on the other hand, if we take 4, information technology will show a upshot as a composite because it is a product of 2X2. I promise now all are articulate about prime numbers.
The following methods are available:
- functions
- if-else statements
- math module
- sympy library
- primePy library
- is_integer office
Method 1: Using isprime() to check if a number is prime or non in python
i.1 Lawmaking
def isprime(num): for northward in range(2,int(num**0.5)+ane): if num%n==0: return False render True print(isprime(seven)) print(isprime(8)) This method is implemented using function. It will return True if the number is prime number. Otherwise, it will render False. Start checking with 7 and so with 8.
Output
True Imitation
i.two Lawmaking
def isprime(num): if num==2 or num==3: return True if num%2==0 or num<2: render Imitation for northward in range(3,int(num**0.v)+1,2): if num%northward==0: return False return True print(isprime(13)) print(isprime(18)) This method is implemented using part. It will return Truthful if the number is prime. Otherwise, it volition return Imitation. First checking with 13 and so with eighteen.
Output
Truthful Imitation
i.iii Code
def isprime(num): if num == 2 or num == 3: return True if num < 2 or num%2 == 0: render False if num < 9: return True if num%3 == 0: render Fake a = int(num**0.5) b = 5 while b <= a: print ('\t',b) if num%b == 0: render False if num%(b+two) == 0: return Faux b=b+6 return Truthful print(isprime(fifteen)) print(isprime(2)) This method is implemented using function. It will return True if the number is prime number. Otherwise, information technology volition return Fake. Kickoff checking with 15 and then with 2.
Output
False True
one.4 Code
def isprime(num): if num> 1: for northward in range(ii,num): if (num % north) == 0: render False return Truthful else: render False print(isprime(64)) print(isprime(5)) This method is implemented using part. It will render True if the number is prime number. Otherwise, it will render False—first checking with 64 and and so with 5.
Output
Fake Truthful
Method 2: Using if-else statements to check if a number is prime or not
n=int(input("Enter a number:")) if n>1: for i in range(2,n//2): if(n%i)==0: print(n,"is not a prime number") suspension else: impress(n,"is a prime number") else: print(n,"is neither prime number nor composite") This lawmaking is usually using loops. Hither we are getting a number as an input from the user. It performs the code and gives the result to the user. If the user gives one as an input, information technology will display neither prime nor composite.
Output
Enter a number:14 xiv is non a prime number Enter a number:3 3 is a prime number Enter a number:ane 1 is neither prime nor composite
Method three: Using math role to bank check if a number is prime or not
Math is a module that is already available in the python library. This module contains a lot of mathematical functions. To access this module, we have to import the module as:
import math
Hither we are using math.sqrt to bank check if the number is prime or not. sqrt() is a born function in python.
Syntax
math.sqrt(x)
Parameter
x – that can be any value.
Returns
It returns the square root of the x value.
Code
import math def isprime(num): a=ii while a<=math.sqrt(num): if num%a<ane: return False a=a+ane return num>1 print(isprime(14)) print(isprime(7)) Output
Simulated True
Method 4: Using sympy module to check if a number is prime or not
Sympy is a module in the python library. It simply depends on mpmath. Here nosotros are simply using a sympy module. The pip command line to install the module is:
pip install sympy
Syntax
sympy.isprime(x)
Parameter
x – it is an input value
Returns
Boolean values
4.1 Code
import sympy print(sympy.isprime(90)) Output
False
4.2 Code
from sympy import * impress(isprime(nineteen)) Output
True
four.3 Code
import sympy.ntheory as nt print(nt.isprime(8)) Output
False
Method v: Using primePy library to check if a number is prime number or not
The primePy is a library that is useful to perform the operations regarding prime numbers. Here we are using primePy to bank check whether a number is prime number or not. The pip control to install the primePy module:
pip install primePy
Syntax
primePy.check(due north)
Parameter
north – Information technology is an input number
Returns
Boolean values
Code
from primePy import primes print(primes.check(63)) Output
False
Method vi: Using is_integer function to bank check if a number is prime or not
is_integer is a built-in function that is useful tos bank check if the given number is an integer or not. It is also useful to check if it is prime or not.
Syntax
float.is_integer()
Parameter
floating number
Returns
Boolean values (True or Faux)
Code
def prime(num): a=[] for i in range (one, num+1): if (num/i).is_integer(): a.suspend(i) if len(a)==2: print("Prime") else: print("Not Prime") prime number(two) Output
Prime
Learn Something New: How to generate a random prime number?
import random def range_primes(a, b): prime = [] for i in range(a, b): is_prime = Truthful for n in range(2, i): if i % northward == 0: is_prime = Imitation if is_prime: prime.append(i) render prime number prime= range_primes(1,100) random_prime = random.pick(prime number) impress("Random Prime Number is:", random_prime) Output
Random Prime number is: xi
1. What is a prime?
Prime number numbers are the numbers that are non the product of any other numbers. These numbers are ever natural numbers.
2. How to check if the number is prime or not using loops?
To check if a number is prime or non. We have to create a for loop to iterate the numbers. Suppose the number is greater than one. It will check whether a number is a product of any number. If it is, it displays False as a result.
Determination
Here we have briefly learned near how to check if a number is prime number or not. We have learned many possible ways. With that, nosotros likewise saw how to generate a prime number number. We hope this article is helpful. Endeavour to solve the programs on your own to proceeds more cognition.
Source: https://www.pythonpool.com/check-if-number-is-prime-in-python/
Posted by: beasleyluxual1965.blogspot.com
0 Response to "How To Find Prime Numbers In Python"
Post a Comment